Interface pc - Arduino Protocol

The interface pc is polling activly (via internet) the SMS/Gateway machine. Consequently the design assumes it can also activly poll the Arduino. ALl it needs is to translate Ethernet/Serial and messageformat.

Interface pc sends a single character and recieves a single character. Polling should be every 5 seconds or so.

interface pc sends
  '?' - Poll/status
  '!' - Launch a ball
  '@' - Reset to Idle

 It should within one second receive a reply
  '?' - Eh? come again. Command invalid or can not comply ('!' while 'B')
  'Z' - Reset has been done (needs to "@" to clear)
  'I' - Ready/Idle state. (needs to "@" to clear)
  'E' - Error condition.  (needs to "@" to clear)
  'B' - Busy, ball rolling
  'W' - Winner has been detected (needs to "@" to clear)
